TMZ
Christian Bale’s rant on the Terminator: Salvation set is probably better than any scene from the movie!
Here is what the Bruce mentioned in the video told E! News about that f*cking bad day:

Bruce Franklin, an assistant director and associate producer on the fourth Terminator film, tells E! News that Bale, a “consummate professional,” just had a bad day.
“If you are working in a very intense scene and someone takes you out of your groove…It was the most emotional scene in the movie,” said Franklin. “And for him to get stopped in the middle of it. He is very intensely involved in his character. He didn’t walk around like that all day long. It was just a moment and it passed.
“This was my second movie with Christian, and it has always been a good experience with him,” added Franklin, who also worked with the actor on 2000’s Shaft. “He is so dedicated to the craft. I think someone is begging to make some noise about this, but I don’t think it’s fair. The art of acting is not paint by numbers, it’s an art form. “

I think I agree with the AP because you can tell he is a very intense actor by his movies and if someone messes up the scene after long hours you can kind of understand why he lost it. But then again I think I will always have a soft spot for him in my heart.
BTW I found it interesting kept switching between his American and English accents.